The diamond drill. (Crystal Falls, Iron County, Mich.) 1887-1996, 1887-06-25

In an interesting and instructive con-
vcrsation with "A drill setter the other
day your correspondent learned great
deal about diamond drills which may
be interesting TO the readers of the Re-
porter, az many OF them are watching
with hope the holes put down in different
parts OF the Lake Superior basin The
first thing to the drill is the bit. This is
a round hollow tube three Fights OF an
inch thick, OF soft maIleable steel, with
thread cut in one end which fits ON 10
the drill proper when used. There are
six to eight diamonds i'm each bit, so ar
ranged as TO cut away the ground both
inside, and outside, and on the bottom
OF the bit. This, il will be seen, leaves a
core OF solid ground inside the bit nearly
as large as it's diameter. Here is the pc
culiar advantage possessed by this drill
The core, which is brought Co the surface
every time the bit is raised, enables the
explorer TO see what kind OF ground he il
drilling in. The method of fastening the
diamonds Co the bit is very simple, but
ment. A hole is first punched or drilled
in the soft drill the diamond insertd,
and the steel tamped closely around it
with hardened steel punches and ham
mer, the cutting face Of the diamond pro-
truding about the thirty-second part Of
an inch. Each bit holds sixteen or
eighteen carats' weight OF these precious
points, which costs about twelve dollars
per carat, so that a bit rugged for boring
costs nearly $225. One bit i'm hard ground
will bore from four TO six feet only, i'm
soft rock forty or fifty feet. After
using the bit is worn away quite thin
IL is then taken out, the diamonds cut
away and inserted in "A new bit and used
over and over again until they them
selves are worn SO as TO be useless. The
diamonds are quite brittle and a small
blow win often crush them, SO copper
punches are used to unloose them from
an old worn out bit. Each drill is pro-
J vided with several bits, and one man is
generally employed ms setter. About
hall day is required TO fix up bit for
use. As the hole reaches greater depth
additional lengths OF hollow steel are
simply screwed together. I'm taking up a
drill the whole lenght is raised by machin-
cry, n lenght unscrewed, and the opera
ton repeated until the last is reached,
which contains the core and bit. A col
umn OF water Is kept running through
the hollow steel pipes, which keeps the
diamonds cool and facilitates cutting.
Steam power Is used, the drill revolving
rapidly. 1t is "fed'' by screw attach
ment which can be regulated according 10
the ground-fast or slow, as the rock is
soft or hard. Three men are required TO
run drill, engineer, fireman and setter.
The cost per foot depend altogether on
the nature OF the ground and depth OF
the hole. Sometimes bit gets fastened
and cannot be raised. The hole is then
abandoned and another started. No
limit has yet been reached in the depth
IL is possible 90 go. With capital and
machinery sufficient il might be poss-
ible 10 bore entirely through the
earth. Some scientist caused n bill Ca
be introduced in the last congress grant
ing SIOO,0 600 forthe purpose oi sinking n
deep hole TO ascertain how thick the
crust OF the earth Is. This would Toe a
good thing provided the hole was bored
on Lake Superior. The diamonds used
are black diamonds or bortz, and arr
found i'm Africa. The diamond drill is a
comparatively new invention. IL Is a
great aid TO exploration. The first one
ON Lake Superior was in 1870, and II
was used at the Superior mine in thif
city. Now they are common, and no
mine prrtends TO do without one or more
They have led TO extensive discoveries
with importantresults Atfirst they had
to surmount prejudice which attaches
TO every new thing, but now every one IL
friendly 20 them, and the results they
give are closely watched.-Ishpeming cor
respondence Milwaukee Mining Reporter
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